Loans and Leases - Accruing and Nonaccrual Troubled Debt Restructured Loans with Payment Default (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013 Loans	Sep. 30, 2012 Loans	Sep. 30, 2013 Loans	Sep. 30, 2012 Loans
Accruing Troubled Debt Restructured Loans [Member]
Accruing and nonaccrual troubled debt restructured loans with payment default
Number of Loans	1		4
Recorded Investment	$ 1,000		$ 1,230
Accruing Troubled Debt Restructured Loans [Member] | Commercial, financial and agricultural [Member]
Accruing and nonaccrual troubled debt restructured loans with payment default
Number of Loans	1		4
Recorded Investment	1,000		1,230
Nonaccrual Troubled Debt Restructured Loans [Member]
Accruing and nonaccrual troubled debt restructured loans with payment default
Number of Loans
Recorded Investment